Musculoskeletal disorders (MSDs) are the leading cause of morbidity and the most common source of chronic long-term pain and disability all over the world. Osteoporosis or bone loss disease is an explosively increasing national MSD. Some predictions indicate a further increase in fracture numbers, resulting in higher-than-before costs for society. A majority of the osteoporotic patients are not identified until after several low-energy bone fractures. The prior art discloses a few methods of diagnosing bone mineral density or osteoporosis, such as, for example, central dual-energy X-ray absorptiometry (DXA), which is a so-called gold standard in osteoporosis diagnostics. In clinical sense, this meauring technique enables a diagnosis of osteoporosis from determined bone mineral density values (BMD) in the femoral neck or lumbar spine. In practice, the determination is performed by comparing the result determined from a patient with the normal values of young women. If the determined result is 1-2.5 normal distributions below average, the patient has osteopenia. If the result is more than 2.5 normal distributions below average, the patient is diagnosed for osteoporosis.
However, the prior art solutions involve some problems. First of all, there is a quite limited supply of X-ray equipment suitable for such a determination, and secondly, the equipment is expensive (typically in the order of about 50 000 to 100 000 , thus not applicable in general healthcare). In addition, the equipment is bulky and requires a room of its own and, because of X-radiation, the measurements conducted thereby always produce a radiation dose for the patient and, especially when measuring an upper segment of the femur, the radiation dose is applied to the close proximity of sensitive internal organs and genital cells. The use of X-ray technology also requires that an operator of the apparatus be familiar with and trained for operating an ionizing radiation source, as well as increases a radiation dose received by the operator. Therefore, the use of a DXA method for the extensive screening of risk groups for osteoporosis on general healthcare level is challenging and, in some cases, even impossible.
The prior art also discloses DXA (pDXA, peripheral DXA) and ultrasonic techniques useful for measuring extremities (for example the heel), which are potential methods for general healthcare level. However, the prognosis provided by such equipment regarding for example density in the upper femur segment is nevertheless poor or at best moderate (r=0.2-0.6) and, hence, the techniques cannot be used very reliably in osteoporosis diagnostics (current care guideline). Indeed, it has been estimated that approximately 40 to 60% of the patients measured with these available techniques must be dispatched to central DXA examination for confirming the diagnosis of osteoporosis.